During the life of an oil well, it becomes necessary from time-to-time to remove debris including sand from the bottom of the bore hole to enhance production. For example, one method that has been employed in the past has been to simply backflush the well bore with a high pressure fluid by means of what is known as a macaroni string. This string is a small diameter length of pipe set in the well bore through which high pressure salt water is circulated in order to flush debris from the bottom of the well bore and to thereby wash out the well bore of sand by a reverse circulation. In such an operation it is not necessary to rotate the pipe. While the macaroni string is useful in some situations, it lacks precise control and therefore has limited application. More sophisticated cleanout techniques call for the precise placement of a tool at or above the level of the debris. Such tools actually pump fluid laden with the downhole debris upwardly from the bottom of the well bore and into the tool. such devices generally both rotate and reciprocate within the well bore, and retain the particulate water and sand of the debris within the tool while recirculating the fluid back to the well bore. The debris is recovered from the well bore by tripping the tool as necessary. Many of these pump-type sand cleanout tools have however been able to effectively handle only limited volumes of material due to their restricted and obstructed construction which includes small ports and passageways, and such devices are subject to having sand jamming up the pump piston in the pump barrel.
Accordingly, a need exists for a sand cleanout tool that can handle larger volumes of material and collect it without fouling the tool due to the solids in the fluids being moved. In addition, a tool that provides for unrestricted flow of materials from the bottom of the well bore in contrast to a restricted flow which enhances fouling of the tool is advantageous.